Promoted hydrogen generation from ammonia borane aqueous solution using cobalt–molybdenum–boron/nickel foam catalyst

Abstract

Ammonia borane (AB) is an intriguing molecular crystal with extremely high hydrogen density. In the present study, by using a modified electroless plating method, we prepare a robust supported cobalt–molybdenum–boron (Co–Mo–B)/nickel (Ni) foam catalyst that can effectively promote the hydrogen release from AB aqueous solution at ambient temperatures. The catalytic activity of the catalyst towards the hydrolysis reaction of AB can be further improved by appropriate calcination treatment. In an effort to understand the effect of calcination treatment on the catalytic activity of the catalyst, combined structural/phase analyses of the series of catalyst samples have been carried out. Using the catalyst that is calcined at optimized condition, a detailed study of the catalytic hydrolysis kinetics of AB is carried out. It is found that the hydrolysis of AB in the presence of Co–Mo–B/Ni foam catalyst follows first-order kinetics with respect to AB concentration and catalyst amount, respectively. The apparent activation energy of the catalyzed hydrolysis reaction is determined to be 44.3 kJ mol −1, which compares favorably with the literature results for using other non-noble transition metal catalysts.